Preparation and properties of ultratransparent NaCl single crystals

The preparation of up to 100 mm diameter single crystalline ingots of ultratransparent NaCl by injecting the reactive atmosphere is reported. The resulting material exhibits high optical quality and bulk absorption coefficient at 10.6 μm of 0.91 × 10⁻³ cm⁻¹, close to the intrinsic value, which makes it suitable for transmissive components in high-power CO₂ lasers.